# a=int(input("请输入一个数："))
# if a==1:
#     print(a,"不是素数")
# for i in range(2,(a+1)):
#     if a%i==0:
#         print(a,"不是素数")
#         break
#     elif a == i:
#         print("是")

prime = int(input("判断素数:"))
if prime==1:
    print('1不是素数')
elif prime==2:
    print("2是素数")
else:
    for i in range(2,prime):
        if prime%i==0:
            print(prime,'不是素数')
            break
        elif i==(prime-1):
            print(prime,'是素数')



